1. Field of the Invention
This invention relates generally to the field of paper cutters and particularly to a device for cleanly shearing the guide edge from a computer paper manuscript.
2. Background Information
A standard type of computer paper (81/2.times.11 inches) for commercially available dot matrix and printwheel computer printers has a construction which includes the basic sheet and a guide edge. The guide edge runs parallel to the long dimension of the sheet on both sides and is connected to the sheet along a perforated line. Equispaced uniform holes are positioned down the center line of each guide edge and permit twin drive wheels to advance the sheet during printing, line feed, form feed, sheet ejection, and manual sheet advance. After the printing process has been completed, the guide edges are typically removed from the sheet by being torn or ripped by hand. Although the perforations are designed to permit clean separation, too often the printed sheet is torn. Of particular difficulty is the situation in which the printed manuscript is thicker than five sheets. Not only is the risk of tearing a printed sheet greater, but also the force necessary to achieve separation becomes too great for most people. At this time, the manuscript must be separated into smaller stacks, resulting in a time-consuming activity.
When using a machine having a cutting blade to cut through relatively large stacks of paper, the paper tends to twist and contort and becomes shredded at the edge being cut; therefore, when using a blade, extreme accurary must be exercised in order to cut the paper to the specific desired dimension.
It may be possible to use a blade to cut relatively large stacks of paper when a large amount of paper on each side of the cut is available; however, when a small amount of paper (approximately one-fourth inch) is to be trimmed off the paper sheets (as is done by the device of the present invention), a knife edge usually results in shredding of the larger side of the paper, resulting in a cumbersome and expensive operation.
The above-noted difficulties are overcome by the device of the present invention which uses the shearing edge of a shear plate to shear the computer paper along a perforated edge thereof.
Additionally, the shearing device of the present invention is safe to use in that no knife edges which may cut the operator's fingers are used. Also, a pressure plate is provided to retain the stack of papers in place for the shearing operation, thus keeping the operator's fingers away from the shearing mechanism.